Game Development, Graphics Programming, GPU, Computer Science

I have a childhood memory (I think it really happened!) that when I first tried HeroQuest with my father, without really reading the rule book, I opened the quest book and setup the entire board for the first quest. On Zargon’s turn, he had a lot of monsters to move! I had also assumed the game was competitive (it’s not – Zargon is more like an AI or DM). That could be a fun scenario, though I think we’d want some sort of anti-camping to prevent a stalement (eg if no heroes do any actions for 10 turns then they lose) (eg every so many turns, more monsters spawn).

Of course it turned out to be a mistake. The map is designed to get revealed as the heroes explore the board, so you only see one new room at a time.

The rules are ambiguous in terms of what it means to “see”, and there’s differences in the European versus American rules. The American rulebook is newer and longer, but I also like to reference the European version as another data point (and the expansions). In some cases, there’s not a clear answer, so I try to pick the most reasonable interpretation in terms of game design.

There’s also different types of “seeing” (of “visibility”) – revealing, casting spells, ranged attacking, searching for treasure, searching for traps, and searching for secret doors. Abstractly, the two types of seeing are rooms and line of sight. For example, you can attack a monster in a different room (through an open door), but when you search for treasure it only applies to the room you’re in (and you can’t search for treasure in corridors).

Revealing Rooms and Corridors When you open a door, does it reveal the full contents of the room? The European instructions clearly answers “yes”:

The American version also answers “yes”:

For corridors, revealing is based on line of sight.

Casting Spells Visibility But what about casting spells in a room? In the previous section, I used the word “reveal”, but the rules only uses the words “see” and “visible” – this suggests you reveal a monster that’s “visible” and you can also cast spells on a monster that’s “visible”. The European instructions explicitly states this.

The American rules say you can only cast a spell on a hero/monster if you have unobstructed line of sight (obstructions include walls, closed doors, and heroes/monsters):

So which version should we use? Can you cast a spell on miniatures in the same room, or do you need unobstructed line of sight?

I like the European version and it’s not clear to me whether the American rule book intentionally made this rule change – it might have been an oversight. The above (pg-15) American example has an Elf in a corridor – they don’t show any examples of line of sight with a hero in a room.

It’s not clearly communicated, but I think the most literal interpretation of the American rules is that you need unobstructed line of sight to cast a spell (and probably for a ranged attack too) (obstructions include walls, closed doors, and heroes/monsters).

My current design decision is to use the European version – if it’s in the same room as you, then you can see it. If it’s not, then use unobstructed line of sight from the caster’s square center to the target’s square center (if the line just touches a corner or wall edge that doesn’t obstruct visibility).

Ranged Attacks Visibility The European version says ranged attacks are the same as spells – so I’m applying the same visibility rules to ranged attacks as spells.

Searching for Treasure Visibility This one is easy. You can’t search for treasure in corridors. In rooms, you can only search your current room.

Searching for Traps, Searching for Secret Doors Here’s what the European version says:

Here’s the American version:

The most obvious part of how to interpret this is – if you’re in a room, your search includes the room you are in. The American version gives us a further clarification that when you search a room/corridor for traps (and I’m interpolating this means secret doors too), you only search that room/corridor – even if an open door is in your line of sight.

But when you search a corridor, exactly which squares do you search? What does “whole room or passage” mean? What does “corridor that you are in” mean? Line of sight is a reasonable answer. A more inclusive answer would be any square that’s already been revealed that your hero can access by normal walking without going through a door/room.

Corridor Walls An interesting corner case is that corridors have walls – and these walls can have a door or a secret door. When walking in a corridor, is a door revealed when you have line of sight to the door’s square center, or to the door itself (such as the wall’s middle point or maybe its two endpoints)? The same question applies to searching a corridor for secret door. I’ve chosen to take a liberal interpretation on this one – line of sight to the wall’s square’s center.

Door Camping is Broken In the following example, when the Elf opens the door – the entire room is revealed. That includes the two corner mummies. However, if the Elf has a crossbow, the Elf can not attack the corner mummies from the doorway because the Elf is not in the room and the mummies are not in the Elf’s line of sight.

However, it is legal to door camp. Heroes can sit at the door and attack through the door using crossbows and spells. Meanwhile, virtually all monsters can only attack adjacent. So Zargon ends up having to fight three against one at the door and hide monsters in the room corners.

Other dungeon crawler board games avoid this scenario by having monsters spawn only after the heroes enter the room, or by giving monsters more powerful ranged weapons.

Overall, HeroQuest door camping is lame and awkward. I’m assuming the original game designers didn’t think it through, and I consider it a design mistake.

An easy way to reduce the effectiveness of door camping is the following rule – you can not cast spells or do ranged attacks through a door. Melee attacks through a door are still fine. With this change, heroes could still door camp, but it wouldn’t be very effective. In most cases, Zargon would just wait.

My HeroQuest implementation emphasizes the authenticity of nostalgia, but I’m still planning to include this anti-door-camping rule (I *might* include an option to disable the rule). It may not be a literal translation of the original game rules, but it addresses the door camping design bug. The design bug was a mistake, so in a sense – the fix is more authentic than a literal interpretation.

Search for traps or secret doors – current room only, corridors use line of sight (excludes rooms) (unobstructed by walls, closed doors).

Line of sight means a straight line from your square center to the target square center. Revealing doors and searching for secret doors, use target square center (not wall middle) – so you can see doors at the end of a hallway even if they are on the side.

Casting spells and Ranged attacking – target any monster/hero in your current room. For corridors, use line of sight (unobstructed by walls, closed doors). You cannot target a monster/hero in a different room – this is the anti-door-camping rule.

One final detail is the question of whether heroes/monsters obstruct your ability to cast spells and ranged attack in a room and/or in corridor. For this issue, I’ve decided to use the European version (with the anti-door-camping tweak).